Often when the belt is slipping you can grab the wheel head and stop it from spinning. Be careful doing, that, though. You don't want to hurt your hands. Do it at somewhat slow speed. Also when it slips during centering it won't necessarily be an even slippage- it'll be a little jerky. If the belt isn't fully seated on the bearing, then there may not be enough friction for the belt to hold, and it'll slip.

Is the wheel slowing because the belt is slipping or because the motor is slowing down under the load? Those are two separate issues. if the belt is slipping because it's not full seated on the bearing, then the new bearing should fix the problem. It could also be a belt tension issue. Is there a way to tighten the belt? Most wheels have a spring mechanism where the motor attaches, that can be adjusted to put more or less tension on the belt. But if the motor is bogging down, then it's under-powered. Is it happening only with larger amounts of clay?
The horsepower rating doesn't mean much. The 1/4hp Soldner can center as much as a Skutt 1/3hp, which can center as much as a Brent 1hp. The controller and pedal have a lot to do with how the power is put to use, as well as the type of motor.

Yes, but small, like the width of a pencil. You're obviously more adept than you give yourself credit for. I see a lot of 8ga type K's that have been bent or broken, and they're pretty tough. You've given me a mental picture of you dancing about your studio with a kiln shelf, like Fred Astaire with a hat rack.

I think you mean direct drive electric vs belt drive? Both can work well or work poorly. It depends on the motor, controller, engineering, etc. The Shimpo whisper series are direct drive, but they use motors that have very poor torque. There used to be a wheel on the market called the Max, and it was crazy powerful. It felt different than a belt drive, though- took some getting used to. Belt drive has been the standard in US wheels for a long time. The old Shimpo wheels were cone drive, they had lots of power. I think Shimpo has sacrificed torque for silence in the whisper series. Alpine made a wheel a long time ago that was direct drive, but it had a gearbox or drive shaft of some sort. The supposedly ran well.

Type S are two very thin wires run through a ceramic sheath that's really not much thicker than a pencil. Very easy to break it it you hit it with a shelf.
Type K are accurate and durable enough for most applications, and cheap to replace. That's why they're standard in kilns here.

@glazenerd how long have yours lasted?
Breakage is a very real issue. I just worked on 4 kilns yesterday that have type S, and replaced the thermocouple on 2 of them due to breakage. They are just so stinkin' thin that it takes very little contact to break them. And that was in a very small professional studio with only 3 people using the kilns. I know I couldn't get through 2000 firings without breakage unless I pulled the thermocouples out of the kiln each time I loaded and unloaded. It's the same thing with APM elements. They last a really long time, but if you get a glob of glaze on them they're done. For most people it's not worth the risk. I definitely recommend type S to some of my customers, though, because they ned the durability and accuracy for higher temps.

The big splash pan on Thomas Stuart/Skutt or Bailey keep the studio a lot cleaner. The 1/3hp TS/Skutt is plenty of power, they have a tone of torque and great controllers. I'm not a big fan of the pedal used on Speedball wheels- it feels really cheap. That said, you get used to whatever you have. Figure that your next wheel will last 20+ years, so get the one you really want.

I guess I was thinking strictly in terms of the moisture from the environment being the only source. Maybe if the piece was washed and wasn't totally dried I can see it remaining in the crazes. But if it was totally dried (like in a heated cycle in a dishwasher), then I don't think it's as likely that the moisture from a humid environment would be taken into the crazing, whereas I could definitely see a porous clay body absorbing moisture from the air.

Yes, you can use any type K you want, although there may be small differences in calibration. You also need to deal with the diameter of the TC. If the one you're using is smaller than the hole in the brick, you need to stuff some fiber into the hole to seal it up.

Seems like Obsidian never should have been made available as a dipping formula. It sounds like it's way to low in clay to be acceptable for dipping. You could try adding 2-3% bentonite to the dry mix. It would give it more durability, but shouldn't be enough to alter the look. A small amount of gum would help with durability, but you'd still be dealing with the added water issue.

Great video! Good, simple yet scientific explanation.
In regards to the image that shows the mold gunk growing in the crazed glaze, I have to wonder if the clay body is fully vitrified, of if it is still porous and that is what is actually holding the moisture, not simply the cracks in the glaze.

@Joseph FThe best way to check your elements is to measure the resistance with a multi-meter. A visual check can also let you know they're shot- if the coils are laying over and bunching up then they're done (probably past done).
@dhPotter I'm not sure about the bisque-cone 6 shedding thing. Probably some difference in the atmosphere or the speed of firing. The metal sheathed ones don't usually shed as bad as the unsheathed, but still do a little bit. I've added protection tubes to several Olympic kilns. It's super easy to drill the brick- I usually drill it close then file it super close, then use the tube itself to do the final little bit. Only takes about 5 minutes. Once you change the TC offset it's good to go.